CLI interface broken due to circular import

[jemrobinson]

✅ Checklist

• I have searched open and closed issues for duplicates.
• This is a problem observed when deploying a Data Safe Haven.
• I can reproduce this with the latest version.
• I have read through the documentation.
• This isn't an open-ended question (open a discussion if it is).

💻 System information

• Operating System: macOS
• Data Safe Haven version: develop @ 1cbb819

🚫 Describe the problem

dsh CLI operations do not work (see log message below). This is likely due to a circular import.

🌳 Log messages

Relevant log messages

╰─ dsh --help
Traceback (most recent call last):
  File "/Users/jrobinson/.pyenv/versions/dsh-jemrobinson-old/bin/dsh", line 7, in <module>
    from data_safe_haven.cli import main
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/cli.py", line 9, in <module>
    from data_safe_haven.commands import (
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/commands/__init__.py", line 1, in <module>
    from .admin import admin_command_group
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/commands/admin.py", line 8, in <module>
    from .admin_add_users import admin_add_users
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/commands/admin_add_users.py", line 5, in <module>
    from data_safe_haven.administration.users import UserHandler
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/administration/users/__init__.py", line 1, in <module>
    from .user_handler import UserHandler
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/administration/users/user_handler.py", line 5, in <module>
    from data_safe_haven.config import Config, DSHPulumiConfig, DSHPulumiProject
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/config/__init__.py", line 1, in <module>
    from .config import Config
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/config/config.py", line 15, in <module>
    from data_safe_haven.serialisers import AzureSerialisableModel
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/serialisers/__init__.py", line 1, in <module>
    from .azure_serialisable_model import AzureSerialisableModel
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/serialisers/azure_serialisable_model.py", line 5, in <module>
    from data_safe_haven.context.context import Context
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/context/__init__.py", line 2, in <module>
    from .context_settings import ContextSettings
  File "/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/context/context_settings.py", line 17, in <module>
    from data_safe_haven.serialisers import YAMLSerialisableModel
ImportError: cannot import name 'YAMLSerialisableModel' from partially initialized module 'data_safe_haven.serialisers' (most likely due to a circular import) (/Users/jrobinson/Developer/data-safe-haven/code/dsh-jemrobinson-old/data_safe_haven/serialisers/__init__.py)

♻️ To reproduce

• Run any dsh CLI command